ATLANTA — Between 2006 and 2010, 1-in-9 sexually experienced women between the ages of 15 and 44 years had used emergency contraception at least once, the National Center for Health Statistics noted in a report released Wednesday. Use of emergency contraception, such as Plan B One-Step, was the most common among women between the ages of 20 and 24 years, those who never married, Hispanic or non-Hispanic white women, and those who attended college.

That compares with 2-in-5 women who used emergency contraception in 2002 and fewer than 1-in-10 women in 1995.

Overall, the study shows that switching emergency contraception products over-the-counter for women older than 17 years has increased access to the treatment and presumably prevented many unwanted pregnancies from happening.

Half of the women who used emergency contraception reported having used it because of fear of failure of another form of contraception. Most women who had used emergency contraception had done so once or twice, the report noted — 59% had used it once, 24% had used it twice and 17% had used it three or more times.

"When looking at age differences, it should be kept in mind that not all women had access to emergency contraception during the earlier portion of their reproductive years," study authors observed in their conclusion. "It was expected that older women would have used emergency contraception less frequently than younger women for reasons of both supply and demand — emergency contraception was not FDA approved in their early reproductive years, and the use of sterilization as a contraceptive method increases with age, consequently decreasing the potential demand for emergency contraception," the authors wrote. "Additionally, differences across marital status and other groups presented here could be confounded by age; for instance, married women are on average older than never-married women."

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